People often carry mobile devices to a venue (e.g., a building) where a pedestrian can access. The venue can have multiple floors. People may want to use their mobile devices to determine on which floor they are located. People may want their mobile devices to display a floor plan of that floor, without having to enter a floor number. Inside the building, determining a floor using global navigation satellite system (GNSS) signals may be impractical due to signal weakness or signal obstruction. An altitude determined using barometer readings may also be insufficiently accurate or certain to determine a floor level, due to measurement uncertainties and atmospheric instabilities.